GCSE Biology - What is Microscopy?
Microscopy: Understanding Light Microscopes
Components of a Light Microscope
- The base supports the entire microscope, connected to the top by an arm.
- A light source, which can be a lamp or a mirror reflecting room light, is located below the stage where slides are placed.
- The microscope typically has three objective lenses with varying magnifications (e.g., 10x, 20x, 50x) and an eyepiece lens at the top for viewing.
Key Terms in Microscopy
- Object refers to the actual sample being observed (e.g., onion cells on a slide).
- Image is what we see through the microscope; it represents the object but may differ in appearance.
How Light Microscopes Work
- Light reflects off a mirror and passes through the object on the stage before entering one of the objective lenses.
- The lenses spread out light rays to create an image that appears larger than the actual object.
Magnification Explained
- Magnification indicates how many times larger an image is compared to its object (e.g., 1000x means image is 1000 times larger).
- The formula for magnification is: Magnification = Image Size / Object Size.
Understanding Resolution
- Resolution defines the shortest distance between two points on an object that can still be distinguished as separate entities.